The original, starring the late Patrick Swayze, established the PG-13 rating with its extensive violence, but it was its story of a world on the brink of World War III that reached out to Cold War frightened fans of the mid-'80s. With the threat of Soviet nuclear annihilation gone, the remake instead looks at a coalition of Russian and Chinese forces.
The war is on American soil, and the invading forces are winning. The story focuses on a group of teens who vow to fight back. Morgan would take the role of the U.S. Special Forces team leader (originated by Powers Booth) who drops in to help the kids fight back.
Not content to get on that high profile project, Morgan is also negotiating hard to take the title role of Lobo, in Guy Ritchie's forthcoming adaptation of the DC Comics property. Lobo is an alien bounty hunter who killed not only his own family, but destroyed his entire planet on a lark. He has a moral code, but he's the baddest bastich who ever rode the spaceways on his flying motorcycle. It's over-the-top with great dark humor, but Morgan proved he could do that, and be huge, with his Watchmen take on The Comedian.
Personally, I can't get enough of Jeffrey Dean Morgan in these kinds of roles. He clearly loves doing them, and he's talented as hell. Nothing can kill a great sci-fi concept faster than crappy acting. At least with Morgan on board, you don't have to worry as much about that.